Tilt type conveyors

ABSTRACT

A closed loop conveyor provides a simple arrangement of tracks on which roll a plurality of cargo carrying devices which are connected to each other by means of a drive chain adjacent one of the tracks and which chain is driven by a sprocket wheel. The chain is of a type having horizontally and vertically pivotal links so that flexibility is provided whereby the tracks can have horizontal bends and vertical slope, the cargo carrying devices thus being enabled to follow a track system which may extend circuitously on the floor of a warehouse and then rise to another floor and ultimately return to the first-mentioned floor. The system is provided with at least one loading station and a plurality of discharge stations at predetermined places along the track circuit. Each cargo carrying device has a normally level load carrying member which can be tilted at any selected station so that cargo can slide gravitationally into a chute or other conveyor means at the selected station, on either side of the track. The drive chain is retained in such a manner that it maintains all of the cargo carrying devices, such units properly disposed on the tracks without any need for additional guide members or specially shaped tracks. The invention is susceptible to use in systems having load carrying members which are trays of sufficient area to support a large cargo load, for example, a postal sack, or where the load carrying members can be relatively narrow slats such that a plurality of slats support an elongated loading. For example, the U.S. Pat. to Atanasoff et al. No. 3,233,720, issued Feb. 8, 1966, and owned by the assignee of the present application, shows a basic arrangement of a plurality of relatively narrow slats wherein several slats can carry a large elongated load, such slats being sequentially tilted at any selected station for discharge.

United States Patent Wooten et a1.

451 June 13,1972

[54] TILT TYPE CONVEYORS [72] Inventors: Robert D. Wooten, Rockville;Warren D. Neal, Walkersville; George J. Elnfeldt, Glen Burnie, all ofMd.

[73] Assignee: Aerojet-General Corporation, El Monte,

Calif.

[22] Filed: Jan. 13, 1970 [21] App]. No.: 2,638

[52] U.S. C1 ..198/155 [51] lnt.Cl ..B65g 15/00 58 FieldofSearch..l98/154,155,158

[56] References Cited UNITED STATES PATENTS 3,510,014 5/1970 Speaker eta1. ..l98/155 X 3,231,066 1/1966 Harrison et a1. ..198/155 3,463,2988/1969 Harrison ..198/155 FOREIGN PATENTS OR APPLICATIONS 57 ABSTRACT Aclosed loop conveyor provides a simple arrangement of tracks on whichroll a plurality of cargo carrying devices which are connected to eachother by means of a drive chain adjacent one of the tracks and whichchain is driven by a sprocket wheel. The chain is of a type havinghorizontally and vertically pivotal links so that flexibility isprovided whereby the tracks can have horizontal bends and verticalslope, the cargo carrying devices thus being enabled to follow a tracksystem which may extend circuitously on the floor of a warehouse andthen rise to another floor and ultimately return to the first-mentionedfloor. The system is provided with at least one loading station and aplurality of discharge stations at predetermined places along the trackcircuit. Each cargo carrying device has a normally level load carryingmember which can be tilted at any selected station so that cargo canslide gravitationally into a chute or other conveyor means at theselected station, on either side of the track. The drive chain isretained in such a manner that it maintains all of the cargo carryingdevices, such units properly disposed on the tracks without any need foradditional guide members or specially shaped tracks. The invention issusceptible to use in systems having load carrying members which aretrays of sufficient area to support a large cargo load, for example, apostal sack,

1,295,249 4/1962 France 198/154 Primary Examiner.loseph WegbreitAssistant E.raminerH. S. Lane Attorney-Edward O. Ansell, D. Gordon Angusand Albert M. Zalkind or where the load carrying members can berelatively narrow slats such that a plurality of slats support anelongated loading. For example, the U.S. Pat. to Atanasofi' et al. No.3,233,720, issued Feb. 8, 1966, and owned by the assignee of the presentapplication, shows a basic arrangement of a plurality of relativelynarrow slats wherein several slats can carry a large elongated load,such slats being sequentially tilted at any selected station fordischarge.

14 Claims, 15 Drawing Figures a Ill" I'ATENTEDm 13 are sum 01 or 10INVENTORS -m MflL T A mmm .D D J N TE RG ERR wm RG ATTORNEYS PATENTEDJuI13 m2 sum 02 or 10 (I 1|||| 9 9m /;{L

PATENTEDJUN 13 m2 3, 569.245

sum as pr 10 PATENTEBJUN 1 3 m2 sum 0? ur 10 Nm 9% 8 wmm 0 9% mmm OwnHAVE PATENTEDJUN13 I972 I swam 0811f 1o PATENTEDJUN 13 m2 sum as or 10PATENTEnJum 1912 3.669245 sum 10 or 10 TILT TYPE CONVEYORS Briefly, theinvention contemplates the provision of a simple, trestle-like supportstructure for a pair of tracks on which roll a plurality of carriages,each carriage having a load support member supported on a pivotallycarried post. A guide track is engaged by each support post rollerwherein the support post effects a vertical level column for support ofthe respective load carrying member. Such guide track is intermediatethe load carrying tracks on which the carriages roll and maintains thesupport post vertical to maintain a level condition of the respectiveload carrying member for loading.

This basic arrangement is not new, being shown in the aforementionedpatent. However, there are several simplifying differences in thepresent invention, as compared to the prior patent, in that thecarriages are not directly articulated to each other as in the priorpatent, but are connected by means of a confined drive chain which alsomaintains them on the tracks. This permits a simplicity of mechanicalstructure as well as affording a system in which the load carryingmembers can follow a curvilinear path in horizontal and vertical planes.The arrangement also simplifies the actual power drive mechanism ascompared with the prior patent which required the load carrying membersto move from an upper to a lower flight on the return run, whereas inthe present invention the return is accomplished by movement around ahorizontally disposed sprocket wheel. Further, in the prior patent thetilting of the slats was maintained by means of special side rails intowhich the roller of each post of a load carrying member moved andremained to the very end of the run. In the present invention such siderails are eliminated and the load carrying members and their posts aresuitably fashioned so that once tilted they remain tilted by virtue ofthe center of gravity being shifted in the tilted position with respectto the pivotal axis.

Other simplifying structure is provided in the present invention as willbe subsequently described and claimed.

A detailed description of the invention now follows in conjunction withthe appended drawing in which:

FIGS. 1A and 1B represent a composite plan view of an over-all conveyorsystem of the kind described herein;

FIG. 2 is a fragmentary elevation partially in section, showing one ofthe tiltable tray units and the chain drive;

FIG. 2A is a chain detail; FIG. 3 is an elevation taken on the sectionline 3-3 of FIG.

FIG. 4 is a fragmentary plan view of one of the tilt control mechanismsfor efiective tray tilting;

FIG. 5 is an elevation on the section line 5-5 of FIG. 4;

FIG. 6 is a longitudinal elevation taken on the section line 66 of FIG.4 and showing the solenoid drive for the tilt control mechanism;

FIG. 7 is a plan view of a device for leveling tilted trays just priorto their approach to the main drive sprocket wheel of the conveyorsystem;

F IG. 8 is a longitudinal elevation on the section line 8-8 of FIG. 7;

FIG. 9 is a longitudinal fragmentary elevation partially in section of amodification of the invention showing a series of tiltable slats inlevel position, together with a common drive chain therefor, wherein theslats are narrower than the trays in the direction of travel and asingle cargo would be carried on a plurality of slats;

FIG. 10 is a transverse elevation partially in section showing thesuspension system comprising rollers for one of the slats of themodification of FIG. 9 and also showing portions of circular guidetracks utilized in this modification;

FIG. 1 1 is a plan view of the modification of the invention at thedrive end of a conveyor loop;

FIG. 12 is a fragmentary plan view of a tilt device for ensuring tiltingof all load carrying members prior to being actuated to level position;

FIG. 13 is a fragmentary plan view of a modified detail of a tiltingmechanism as used at a discharge station.

Referring to FIGS. 1A and 1B, the over-all system comprises a pair oftracks 10 and 15, suitably supported on structural framework asindicated at 18 and forming a complete conveyor loop, the configurationof which is a matter of choice depending on specific installation anddesired location of a loading platform 22 and discharge stations such as25. Several loading platforms can be used.

Rollable on the tracks are a plurality of articulated trays 30 which aremaintained in level position by means of certain components to bedescribed co-acting with a guide track 35 which extends intermediate thetracks 10 and 15. All of the trays are articulated by means of a drivechain 40 which makes a complete loop suitably guided so as to follow theconfiguration of the tracks. Each tray is secured to the drive chain 40and the drive chain is in turn driven by a large sprocket wheel 45,having suitable structural bearing support as at 48 on a vertical axisand being rotated via a chain 52 coupled to a reduction geared motor 55.

Upstream of the drive sprocket wheel is disposed a fixed tilt channel 58and leveling means 60 which serve the purpose of tilting any level trayand then leveling all trays going to the sprocket wheel.

The directional arrows D in FIGS. 1A and 1B show the direction movementof the trays in their circuit about the loop, and it will be noted thatthey pass a loading platform 22 which may be of manual or automatictype, and subsequently move past discharge station 25. Prior to eachdischarge station is a tilt control mechanism 65, whereby any tray canbe tilted in either direction (FIG. 3) so that cargo thereon can slidein the respective direction onto a suitable conveyor or other receivingmeans, e.g., a chute at any discharge station 25 It will be appreciatedthat tray loading and discharge at selected stations, and conveyorcarry-off thereat can be in accordance with any programmed system, inaccordance with known prior art and which system does not form any partof this invention.

Suitable guides and wear surfaces are provided for the chain 40, forexample, a channel 68 (also see FIG. 3) and an arcuate wearstrip 72around which the chain rolls in traversing any bend in the system, forexample, as shown for the return bend in FIG. 1B.

Normally, channel 68 retains and confines the chain for movement in apredetermined path, and the chain effects retention of cargo carryingdevices having transversely tiltable load carrying members, all ashereinafter des-cribed, such re tention being on the tracks 10 and 15 byvirtue of confinement of the'chain.

Referring to FIGS. 2 and 3, each tray 30 will be seen to have fore andaft flanges 75a/75b, respectively, with a spacing therebetween such thatthe tray is sufficiently long in the direction of travel andsufficiently wide transversely thereto to carry a cargo unit. Forexample, a packing carton or a mail sack which may be of the order of acouple of hundred pounds in weight or more. Fore flanges 75a aresomewhat shorter than flanges 75b, transversely. The tray is made ofstamped, heavygauge sheet metal and is supported by a pair of sheetmetal brackets 78 which are bolted as at 82 to reinforcing ribs such as85 pressed out of the bottom of the tray. The brackets 78 have verticalflanges 88 bolted as at 92 to respective sides of a support post 95which serves as a column for supporting the tray and its load. Post 95has a section 96 with hearing collar 100 integral therewith from whichdepends a tilt-control arm 104 integral with the collar. Collar 100 ispivotally carried on a pin 108, having its ends supported in verticalflanges 112, suitably secured as by a welded construction in conjunctionwith abutment plates to a base plate of a tray support carriage 125. Thebase plate 120 has a suitable opening 128 through which the arm 104descends, whereby the arm can rock on pin 108 in a transverse verticalplane when actuated in a manner to be described by engagement of a guideroller 132 carried at the lower end of arm 104. Roller 132 normallyrides in the guide track 35 to maintain the post 95 vertical and thetray level. Rocking of the post and thus tilting of the tray can beefiected by switch levers and cam mechanism indicated by the referencenumeral 65 in FIG. 1B and as shown in detail in FIGS. 4 and 5, laterdescribed.

Still referring to FIGS. 2 and 3, each carriage 125 has side flanges 135which carry outrigger rollers such as 138 on stub shafts, there beingfour such rollers in order to provide rolling support for the carriageand thus for the post 95 and tray 30 of the respective carriage. Therollers 138 roll on horizontal flanges 142 of respective tracks andwhich may be comprised of channel members having opposite flanges boltedto the structural framework 18, as shown in FIG. 3. Thus, tracks 10 and15 can be conventional channels bolted as at 146 to side angle members150 comprised in framework 18, and having floor support members 154.

The guide track 35 may be suitably carried on a horizontal bed plate 158of the support structure 18 which comprises trestles 162 made up ofangle irons 165 and 166 to which plate 158 is attached.

The chain 40 (FIG. 3) is retained in chain track 68 which may be achannel member as shown and suitably secured as by welding to angle ironmembers such as 174 periodically spaced and secured to the web of thechannel which comprises track 15. It will be noted that chain 40 is thusretained in its channel track 68. The chain is secured as by pins 178 tothe base plate 120 of the carriage. As seen in FIG. 2, each carriage issecured by two spaced pins 178 to the chain and the spacing between suchpins is equal to the pitch of the chain which is the distance betweenrollers such as 182 that ride in the chain track 68. The distancebetween rollers is, of course, such as to fit between teeth of thesprocket wheel 45 (FIG.1A) which can be made as radially extending rodsfor all practical drive purposes. The chain 40 comprises pairs ofparallel long links such as 184 and short links such as 188. Betweeneach pair of parallel long links 184 there are short links 188 pinned asby pins 192 to the adjoining ends of the contiguous long links. Theshort links have solid ends through which pass pins 192 via bores, andare pivotally connected as by pins 196 in a plane at right angles to theplane of pins 178 and 192. The short links can bs of a tongue and slottype, as shown in FIG. 2A. Accordingly, chain 40 can pass around bendsin a horizontal plane by virtue of pins 178 and 192, and can also bendin a vertical plane by virtue of pins 196.

From the foregoing, it will be appreciated that the conveyorconstruction is thus not limited to movement of the trays in ahorizontal plane, but that, in fact, the track construction can befabricated to move trays on upward and downward slopes, for example,from floor-to-floor in a storage warehouse.

It will be noted that the pivotal chain links, such as 184 and 188, areomitted below the carriage base 120 of the tray, but that chain tensioncontinuity is provided for by a pair of links such as 200 which extendspacedly between rollers 182 and are connected thereto at the link endsby the pins 178, which pins being secured to carriage base 120, tiesthat base to the chain. The distance between pins 178 attached to base120 is not so great as to preclude movement of the carriage in an arc ofsuitable radius in a vertical plane, considering that the local sectionsof the chain upstream and downstream of the carriage are provided withhorizontal pivot pins 196 to render sufficiently flexible the length ofchain underlying the respective tray and carriage.

Referring to FIG. 3, the phantom line positions of the tray 30 show thetransversely tilted positions to left and right of the path of movementfor cargo discharge. The carriage 125 has rubber-cushion bumper buttons205 which are carried by inclined flanges 208, extending from the sidewalls 135. When a tray is tilted, a reinforcing rib 85 engages one ormore buttons 205 to act as a cushioning stop, in either direction oftilting. The center of gravity of the tray, or any load carrying memberincluding its integral components, is shown generally at C. G., beingabove the pivotal axis. Accordingly, the tray remains in either tiltedcondition.

Referring to FIGS. 4, 5 and 6, the tilt control mechanism 65 isillustrated which comprises certain switching elements which the guideroller 132 engages, in accordance with selected control for the purposeof rocking the support post by engagement with cam members to effecttilting of the tray.

In the plan view of FIG. 4 the guide track 35 has an upstream portionshown as guiding a guide roller 132 (solid lines) toward the mechanism65 in the direction of the arrows, and the upstream portion extends to apair of triangular horizontal cam members 212 having outward slopingedge surfaces such as 215. In the event of roller 132 having beenpreviously actuated to tilt its respective tray, it would necessarily beas shown in phantom in FIG. 3, either to the left or to the right of theerect position. If either position shown in'phantom in FIG. 3 wereretained during the course of subsequent travel of the tray, roller 132and respective post 95 would clear switch mechanism 65 without harm.However, owing to possible mishap, such as failure of a load to slideoff a tray and causing an unbalance,a post 95 and roller 132 may be in aposition such that roller 132 might bounce and drag against the side ofthe track 35 on the exterior thereof. In such case, either cam edge 215would engage roller 132 dependent on which side of track 35 it was on,to insure full angularity of post 95 so as to clear all elements ofswitch mechanism 65 without collision or interference. The pair of cams212 are simple triangular plates carried by vertical guide plates 218which form short extensions downstream of the portion of upstream track35. It will be understood that assembly of these components can readilybe effected as by welding to track 35 and to a horizontal plateextension 220 and respective curved guide plates 222.

Plates 222 form initially linear extensions of respective plates 218,and thereafter curve to join respective tilt cams 225, there being apair of such cams supported as by welding to respective angle ironsections 228 and sloping outwardly in the downstream direction. The cams225 may be rods or rails which diverge, as shown in FIG. 4 A pair ofinwardly disposed cams 232 having divergent portions are carried onangle iron sections 235. Thus, portions of cams 225 and cams 232 areparallel to constitute a divergent channel on each side of thecenterline of travel of the trays 30 with respect to tracks 10 and 15.

The downstream ends of cams 232 assume parallelism. However, it shouldbe particularly noted that such downstream ends of cams 232 terminateshortly beyond the switch mechanism 65 as seen in FIG. 4, and are onlylong enough to ensure full tilt of post 95. In other words, once a trayhas been tilted it remains tilted by virtue of its own unbalance untilthe end of its run as it approaches the leveling mechanism 60 of FIG. 1Aand there is no need to extend cams 232 for the purpose of maintainingconstant engagement with roller 132 to insure maintenance of tilt.

As seen in FIG. 4 a central guide channel is formed by a sequentialarrangement of members, such channel being indicated by the straightline of arrows from the upstream end of track 35 to the downstreamcontinuation guide channel effected by plates 239.

Thus, a composite central guide channel traverses the tilt controlmechanism 65 and is comprised of plates 218, the parallel portions ofplates 222, the opposed respective straight and parallel portions of apair of switch arms or levers 238L and 238R, and the pair of parallelplates 239 which are secured to a base 240.

With the switch levers in the non-actuated position as shown in fulllines in FIG. 4, all rollers 132 will pass through the central guidechannel formed by the above described aligned members and no tiltingwill take place.

Actual tilting is readily effected by the downstream divergentangularity of the cams with respect to the centerline of the track 35 inconjunction with switch arms or levers 2381.. and 238R.

The cams are given some upward slope although maintaining generalparallelism for the channel portions described, since it is obvious fromFIG. 3 that as roller 132 swings transversely left or right it is movingupwardly in an arc. Hence, the

upward slope insures engagement of the cams with the roller 132 untilultimately the roller rides along the downstream segment of either cam232 parallel to tracks and 15. The tray is then fully tilted for cargodischarge by gravity, the cargo sliding on to a station conveyor, e. g,a chute as shown at 25 in FIG. 3.

From all the foregoing, it will be apparent that by virtue of the centerof gravity of the tray and post 95 assembly being displaced out of thevertical plans containing the pivotal axis of post 95, such tray oncetilted would normally reamin tilted until subsequently levelled by theinstrumentality 60. However, since mishaps are always possible, the cams212 are provided upstream of each switch mechanism 65 so as to rendercertain full tilt of any tray in the event that it was not actuated tofull tilt position, or for some reason was swung back in the course ofits travel to less than full tilt position, all as previously set forth.

The support means for the various angle iron sections such as 228 and235 is comprised of a channel member base 240 to which such iron anglesmay be welded and which channel member base 240 has flanges 241suspended as by angle iron elements 243 to the lower flanges of tracks10 and all as clearly shown in FIG. 5.

Channel member 240 also supports the switch levers 238I. and 238R andsolenoid actuators therefor for diverting rollers 132 toward the left orright by actuation of respective switch levers. Thus, switch levers 238Land 238R effect diverting of rollers 132 to the left and rightrespectively.

Lever 238R is pivoted by pin 258 to the web of base 240 with suitablespacing collars, as shown in FIG. 5, and the lower end of the pin hasrigidly secured thereto a lever 260 which, as seen in FIG. 6, isarticulated via a link 264 to the plunger 267 of solenoid 270. Normally,the lever 260 is maintained in position by a tension spring 274 suitablysecured to base 240, so that the switch lever is maintained in theposition shown in solid lines on FIG. 4. If, however, solenoid 270 isenergized, lever 260 is swung to actuate switch lever 238R to the dottedline position whereat it blocks the channel from track 35 and plates218, causing the approaching roller 132 to ride on the guiding edge camsurface 238R of the lever so as to ride between the right-hand pair ofcams 225-232, as shown in the upper portion of FIG. 4, roller 132approaching from the right. When the solenoid is de-energized spring 274pulls switch lever 238R back to the normal position and, assuming thelevers in the position shown in FIG. 4, all rollers 132 thereafter canthen traverse the switch mechanism 65 without being acted upon, ridingbetween the switch levers and guide plates carried by base 240 andforming a guide channel to the downstream portion of track 35 from thechannel formed by the spaced levers.

In a completely similar manner, a respective solenoid 280, actingthrough a lever 284 and a pivot pin 288 to which the switch lever isattached, as well as a spring 292, effects control of switch lever 2381.so as to move it to the phantom line position for diverting roller 132to the left to effect tilt by the action of the cam pair 225-232 at theleft of the path of approach of roller 132.

The action for control of switch lever 238L is identical to that ofswitch lever 238R, and need not be further described.

Preferably, a rubber cushion bumper, such as pad 296, fastened to anangle 300 is disposed at each side of a respective switch lever tocushion the effect of pull back of respective springs, and also toensure the switch levers being in proper aligned initial position toreadily permit rollers 132 to pass therebetween when no tilting is tooccur.

It should be noted that the upstream end of switch lever 238L is bent(FIG. 6) so as to be in a lower plane than the lever 238R, in order thatthe levers will not interfere with each other when either lever isactuated. The extent of actuation of the switch levers is governed bythe extent of travel of the respective solenoid armatures, althougheither lever could engage the opposite pad 296 as a limit stop as willbe obvious from FIG. 4.

FIGS. 7 and 8 illustrate the leveling means 60 which levels all traysprior to reentry to the upstream side of the drive sprocket wheel 45(FIG. 1A). Thus, tracks 10 and 15 are fragmentarily disclosed in FIG. 7,and it will be understood that tilted tray, as evidenced by the guideroller 132, shown in solid lines for an exemplary tray, is moved in thedirection of the arrows.

The upstream section of guide track 35 terminates prior to the beginningof the leveling means 60 and a downstream portion begins at thedownstream end, as will be apparent from consideration of FIG. 7. Thus,the upstream portion of the guide track will, as noted on FIG. 1A, leadguide rollers such as 132 into the leveling means, while the downstreamportion will receive the rollers, the trays then being leveled, andguide the tray around the sprocket wheel 45, maintaining the levelcondition.

As seen in FIG. 7, the leveling means comprises a bed plate 310 securedin any suitable manner to the tracks 10 and 15. The bed plate may be achannel having flanges bolted to the tracks, as indicated, and having asurface flush with the surface of bed plate 158, shown as upstream anddownstream sections, and which latter bed plate supports the guide track35 as heretofore described, which is thus interrupted at the levelingmeans 60.

The leveling means comprises a pair of converging cams 315 which may bedownwardly sloped in the direction of roller movement, secured as bystructural angles 320 to bed plate 310 in a completely symmetricalarrangement wherein the widest portion of cams 315 forms a mouth intowhich rollers 132 in tray tilted condition have entrance. It will bereadily understood that whether the trays are tilt-ed left or right, oneor the other will gradually swing the roller, and therefore itsrespective tray, back to a tray level position, such position beingreached at the narrowest downstream spacing between cams 315 wherein therollers then pass through an exit guide track section 324 secured byguide plates 328 to the downstream guide track section 35.

While it might normally be thought that no further mechanism is requiredfor leveling of trays other than cams 315 which serve as leveling cams,owing to the speed of travel of the trays and to the fact that certaintrays may arrive at the leveling means in level condition, it has beenfound that positive control of tray angle is highly desirable to preventwild oscillation and erratic behavior. In other words, the trays shouldbe kept under positive control at all times while being manipulated fromtilted to level position. Accordingly, the leveling means also comprisesa guide cam plate 330 pivoted as by a pin 334 to bed plate 310 so thatit can pivot in a horizontal plane. The pivot point is upstream of plate330, while the downstream end is supporting rollably on a ball 338suitably carried and secured to the under side of plate 330, as by asocket 342. Accordingly, plate 330 can swivel from the solid positionshown in FIG. 7 to the dotted line position with a minimum of frictiondue to the rolling of ball 338 on the surface of bed plate 310, andbetween the limits provided by the extending tongue end 346 of plate 330which can engage in either direction with a cushion pad 350 secured toan angle 353, such limit stop being provided on each side of exit track324. Plate 330 will always be in one position or the other, i.e.thesolid and dotted line positions of FIG. 7, depending on which side thelast passing tray was tilted, being held by friction at pin 334.

The edges of plate 330 are cam-shaped, being identical in shape on bothsides of the plate, which for lightness has a large cutout 356 at itscenter in order to reduce the effect of angular inertia. The upstreamend of plate 330 is formed with a rounded apex portion 360 of fairlysmall radius, such that the major portion of the rounded surface is toone side or the other of the centerline of upstream track section 35, orat least not dead centered therewith.

It will be apparent that tilted rollers 132 approaching the levelingmechanism can engage initially either a straight portion 368 or 368a onone side or the other of cam plate 330, or

initially somewhere along a curved portion 365 or 365a leading to thestraight portion, swinging the plate to effect a guide channel inconjunction with a fixed cam member 315.

Referring to FIGS. 9, 10 and 11, a variation of the invention isdisclosed wherein relatively narrow load carrying members 400 areutilized of the general type shown in the previously mentioned patent toAtanasoff et a1 U.S. Pat. No. 3,233,720. In such type of narrow slatconveyor system, a plurality of slats carry a single cargo unit, all asdescribed in that patent. However, where it is desired to use narrowload carrying members in the present invention, a problem arises due tointerference of the radially inner ends or corners of the slats inpassing around a sprocket wheel such as the sprocket wheel 45 of FIG.1A. Due to the close adjacency of the transverse sides of the slats,when the slats are angled with respect to each other the corners ofadjacent slats will approach each other and might clash, assuming veryclose slat spacing. This problem has been overcome in a very novelmanner, albeit, quite simply, by tilting the slats as they pass aroundthe sprocket wheel.

Thus, as seen in FIGS. 9, 10 and 11 all reference characters previouslyused are repeated for identical or substantially identical parts, andhence no further description thereof need be given. However, thenormally straight guide track 35, as seen in FIG. 9, is deflectedinwardly in a bent section 410 as seen in FIG. 1 1, radially closer tosprocket wheel 45, and then passes arcuately about sprocket wheel 45below the chain wearplate 413 leaving the downstream side thereof in theoutwardly bent section 415.

The arcuate portion of track 35 is sloped as indicated by thefragmentary portion 420 in FIG. 10 in order to maintain the flanges ofthe channel section parallel to the axis of the guide roller 132 whichremains in the track. Thus, due to the inward bend at 410, each slat istilted in turn so that their outer ends move downwardly to thereby opena spacing such as 425 at the inward ends, between slats, in order toprevent comer interference.

At the downstream bend 415 the slats are once more tilted to levelcondition.

Referring particularly to FIG. 9, it will be noted that the chain 430 issomewhat different from the chain 40 of FIG. 2 in that only single linksare needed between carriages 125, this being due to the closer spacingof the carriages when narrow slats 400 are used. However, the biplanarconstruction of the chain is carried out in the same manner by means ofvertically and horizontally disposed pins, as heretofore described inconnection with FIG. 2 and as will be readily understood by personsskilled in the art.

While a channel like the channel 68 (FIG. 3) for the chain could becircuitously formed to guide the chain around the bend (FIGS. 18 and10), it has been found expedient to use a wear strip 413, of plasticmaterial, e.g., polyurethane. Such strip can readily be secured as byrivets (not shown) to the inner track.

It will be appreciated that a wear strip is usable also for the doublelink chain of FIG. 2. Such wear strip 72 is shown in FIG. 1B.

As seen in FIG. 10, a channel 435 guides the rollers 178 at one side ofthe carriage 125 and has aflange above such rollers.

Such channel 435 is preferably used around the radially inner rollers toensure no vertical movement of the carriage and chain above the innersupport track 10 and wear strip 413 (FIG. 1B). The channel is also used,but not shown, to capture the outer rollers of carriage assembliestraveling around the drive sprocket wheel to ensure no undesirabletilting of the carriage.

It has been found preferable to provide tilt of all trays prior to theirentry to the leveling means 60 and a device is shown in FIG. 12,indicated by the reference character 58 in FIG. 1A, to make certain thatall trays are tilted prior to entry to the leveling mechanism. Thus, inFIG. 12, a base plate 450 of the same type heretofore described for thebase plate 240 is secured between the tracks in the same manner as baseplate 240 (FIG. 5) and carried on the base plate is a fixed cam 455,generally S-shaped, and which may be of rod construction such as cams225 and 232 (FIGS. 5 and 6).

A parallel cam comprises the fixed cam 460 having a pivotal cam 470disposed as an extension thereof and pivoted as by a pin 475 to the baseplate.

Accordingly, the fixed cams 455, 460 and pivotal cam 470 effect achannel 472 from the downstream end of guide track 35 for guide rollersof level load carrying members such as rollers 132, as have heretoforebeen previously discussed, and such channel causes tilting by virtue ofthe lateral offset or bending of the channel so that when such rollersarrive at the leveling mechanism 60 their load carrying members arefully tilted and then enter the levelling mechanism to be levelledbefore going to the sprocket wheel 45 of FIG. 1A.

The pivotal cam 470 which forms an extension end of the cam 460 may be abar suitably curved to give smooth roller path transition and may as amatter of design rise upwardly in a vertical plane so as to continue theupward rise of cam 460 for the purposes of remaining in assured contactwith rollers as they are tilted and thus move in an ascending arc (FIG.3) to tilt position. Such upward rising of the cams is illustrated forthe cams 225 and 232 on FIG. 6.

Sleeves or collars may be utilized below cam 470 in order to situate itat the proper initial level at the pivot pin 475.

Persons skilled in the art will fully understand the construction anddesign of cams for effecting the functions described and no furtherdetailed discussion need be given. However, at this point it might bementioned that all cams utilized in this system could be level and haveno upward rise provided rollers 132 had sufficient axial length tomaintain contact with them during the course of being tilted and whilemoving transversely in an upward swing, FIG. 3 illustrating such upwardswing in degree for full tilt.

Further referring to FIG. 12, it will be appreciated that theconstruction provides for tilting of any level load carrying member whenit arrives at the tilting mechanism 58 coming from the direction of theright hand arrow A. However, should a load carrying member arrive inalready tilted condition, the roller 132, shown in full lines, willengage cam 470 and swing in out of the way so as to pass unimpeded tothe leveling mechanism 60. Likewise, should a load carrying member betilted in opposite direction so that the roller is approaching on theopposite side of the channel 472 it will simply traverse the tiltingmechanism without engaging any component.

The pivoted cam member 470 need not be biased to any position. Thepivotal pin mount is made suitably tight to effect a frictional holdingeffect for the position shown, or if this cam be swung by a tiltedroller 132 so as to block channel 472, then any roller comingtherethrough will push it back to the position shown. The verticalflange of base plate channel 450 serves as a stop for such returnmovement.

Referring to FIG. 13, a fragmentary portion of a switch lever mechanismof the type shown in FIG. 4 is illustrated, all reference charactersbeing identical with that on FIG. 4, and wherein a pivotal cam extensionend 470 as hereinabove described has been pivoted as by a pin 475 to thebase plate 240. The purpose and action of the pivotal cam member 470 isprecisely as described in connection with FIG. 12 and need not berepeated save to say that it efiects a smooth transition for rollerspassing between the cams 225 and 232 in being transversely actuated totilt load carrying members. Obviously, both of the cams 225 shown inFIG. 4 would be provided with such end cam members 470 as mirror imagesof each other so that either of the divergent channels would affordsmooth tilting transitions.

We claim:

1. A conveyor system comprising extended track means and plurality ofcargo carrying devices movably supported thereon; a chain connectingsaid cargo carrying devices; said chain being flexible in a horizontalplane and drive means for actuating said chain; and chain retainingmeans for confining and guiding said chain whereby said chain maintainssaid cargo carrying devices on said track means; wherein said trackmeans comprises a pair of spaced channel members and said chainretaining means comprises a channel member carried by one of said trackmembers, said chain having a plurality of rollers disposed in said chainretaining channel member whereby said rollers are laterally confined byflanges of said latter channel member; said cargo carrying devices eachcomprising a load carrying member and a carriage, pivotal support meanswhereby said loading carrying member is tiltably carried by respectivecarriages so as to be tilted reversibly in a plane transverse of theplane of movement of said cargo carrying devices; a tilt controlmechanism incorporated in said track means and comprising a first pairof cams (225) having a common origin and divergent spacing therebetweendiverging in the direction of movement of said cargo carrying devicesand further comprising an additional pair of cams (232) having portionsspaced inwardly and parallel to respective cams in said first pair ofcams to effect a pair of divergent channels in correspondingly divergentdirections; guide follower means carried by said cargo carrying devicesreceivable in either divergent channel and connected to respective loadcarrying members to effect tilt thereof when said guide follower meansis received in one of said channels; including a pair of switch leversfor effecting diverting of said guide follower means selectively toeither divergent channel.

2. A system as set forth in claim 1, wherein each cam of said first pairof cams has a guide member pivotally mounted at a downstream end thereofand effecting an elongation of the respective divergent channel; whereinsaid guide members can be engaged by and pivoted out of the path of theguide follower means of load carrying members which have been previouslytilted.

3. A conveyor system comprising extended track means and plurality ofcargo carrying devices movably supported thereon; a chain connectingsaid cargo carrying devices; said chain being flexible in a horizontalplane and drive means for actuating said chain; and chain retainingmeans for confining and guiding said chain whereby said chain maintainssaid cargo carrying devices on said track means;

said cargo carrying devices each comprising a load carrying member and acarriage, pivotal support means whereby said load carrying member istiltably carried by respective carriages so as to be tilted reversiblyin a plane transverse of the plane of movement of said cargo carryingdevices; a tilt control mechanism incorporated in said track means andcomprising a pair of cams (225) having divergent spacing therebetween,said cams diverging in the direction of movement of said cargo carryingdevices; said tilt control mechanism further comprising an additionalpair of cams (232) having portions spaced inwardly and parallel torespective cams in said first pair of cams to effect channels incorrespondingly divergent directions; and guide follower means carriedby said cargo carrying devices receivable in said channels and connectedto respective load carrying members to effect tilt thereof when saidguide follower means is received in one of said channels, including apair of switch levers to efiect diverting of said guide follower meansselectively to either divergent channel; said switch levers beingspacedly mounted and having respective opposed edges substan tiallyparallel and normally forming a guide channel intermediate said pairs ofcam members, means pivotally actuating said levers; actuating means forpivotally actuating said levers; each lever effecting an extension of aside of a respective divergent channel when it is actuated to therebyeffect diverting; wherein said switch levers effect a path through thespacing therebetween when not actuated so as to guide said guidefollower means through said tilt control mechanism without effectingtilting, and wherein either lever, when actuated, guides said followermeans to a respective divergent channel to effect tilting.

4. A system as set forth in claim 3, and respective spring bias meansfor normally maintaining said switch levers in position to efiect saidspacing therebetween, said actuating means for said levers beingselectively operable for either lever pivotally.

5. A conveyor system comprising extended track means and plurality ofcargo carrying devices movably supported thereon; a chain connectingsaid cargo carrying devices; said chain being flexible in a horizontalplane and drive means for actuating said chain; and chain retainingmeans for confining and guiding said chain whereby said chain maintainssaid cargo carrying devices on said track means; said cargo carryingdevices each comprising a carriage having a load carrying member andsaid load carrying members being tiltably carried by respectivecarriages so as to be tilted reversibly in a plane transverse of theplane of movement of said cargo carrying devices; a tilt controlmechanism and a guide track leading thereto; said tilt control mechanismcomprising a pair of cams (225) having divergent spacing therebetween,said cams diverging in the direction of movement of said cargo carryingdevices, and said tilt control mechanism further comprising anadditional pair of cams (232) having portions spaced inwardly andparallel to respective cams of said first pair of cams to form divergentchannels; respective l-oad carrying members having guide follower means(132) receivable by said guide track (35) for guidance to said divergentchannels whereby to effect tilting in a respective rotative directionwhen said guide follower means is received in one of said divergentchannels, including a pair of switch levers (238R, 238L) for effectingdiverting of said guide follower means selectively from said guide trackinto either channel; each cam of said first pair of cams (225) having apivotally mounted extension end (470) thereof effecting an elongation ofthe respective divergent channel; the said pivotally mounted extensionends being en gageable by unguided guide follower means entering saidtilt control mechanism so as to be swung out of the path of said guidefollower means, thus permitting said guide follower means to moveunimpeded exteriorly of either divergent channel.

6. A system as set forth inclaim 5, said guide track being disposed inalignment with the spacing between said switch levers when said switchlevers are not actuated; and cam members disposed on opposite sides ofsaid guide track to be engaged by any guide follower means to effectfull tilting of the respective load carrying members in the event thatany such guide follower means is approaching said tilt control mechanismaskew of said guide track, in order to insure clearance of any suchguide follower means in respect to said tilt control mechanism to movewithout interference therepast.

7. A conveyor system comprising extended track means and plurality ofcargo carrying devices movably supported thereon; a chain connectingsaid cargo carrying devices; said chain being flexible in a horizontalplane and drive means for actuating said chain; and chain retainingmeans for confining and guiding said chain whereby said chain maintainssaid cargo carrying devices on said track means; wherein each said cargocarrying device comprises a carriage having a load carrying member witha support post pivotally carried by the respective carriage, said loadcarrying members and said support posts having a center of gravitydisposed in a vertical plane with the pivotal axis thereof when saidload carrying member is in level position and said center of gravitybeing disposed above said pivotal axis, whereby when said load carryingmember is in tilted position it remains in tilted position by virtue ofthe displaced center of gravity; said track means including a tiltcontrol mechanism and having a guide track extending to said tiltcontrol mechanism upstream thereof and a continuation of said guidetrack extending from said tilt control mechanism downstream thereof;said tilt control mechanism comprising a plurality of members effectingdivergent channels diverging directionally downstream; switch controlmeans intermediate said divergent channels comprising levers having aspacing therebetween aligned with said guide tracks and effecting acentral channel in conjunction therewith and relative to the divergencyof said divergent channels; said support posts having respective guidefollower means movable from said upstream guide track through saidcentral channel to the downstream guide track and maintaining said postsvertical so that respective load carrying members are maintained levelwhen respective cargo carrying devices move past said tilt controlmechanism; means for actuating either of said switch levers to guide aguide follower means into a diverging channel for efiecting tilt of arespective load carrying member; cam means (212) upstream of said switchlevers disposed adjacent said upstream guide track to tiltably divertany guide follower means misaligned in approaching said tilt controlmechanism so as to permit passage thereof without interference with saidtilt control mechanism.

8. A conveyor system comprising extended track means and plurality ofcargo carrying devices movably supported thereon; a chain connectingsaid cargo carrying devices; said chain being flexible in a horizontalplane and drive means for actuating said chain; and chain retainingmeans for confining and guiding said chain whereby said chain maintainssaid cargo carrying devices on said track means; wherein each said cargocarrying device comprises a carriage having a load carrying member witha support post pivotally carried by the respective carriage, said loadcarrying members and said support posts having a center of gravitydisposed in a vertical plane with the pivotal axis thereof when saidload carrying member is in level position and said center of gravitybeing disposed above said pivotal axis, whereby when said load carryingmember is in tilted position it remains in tilted position by virtue ofthe displaced center of gravity; said track means comprising a levelingmechanism upstream of said drive means for leveling load carryingmembers arriving at said leveling mechanism in tilted condition; saidleveling mechanism comprising a pair of fixed converging cam members andsaid support posts having guide follower means engageable with either ofsaid cam members dependent upon respective direction of tilt of saidsupport posts, whereby said cam members effecting swinging of supportposts to substantially vertical condition to level respective loadcarrying members; guide track means extending from the convergent endsof said cam members to said drive means to receive said guide followermeans as they leave said convergent ends with the respective postssubstantially vertical; and a pivotal cam plate intermediate said fixedconvergent cam members and pivotally mounted upstream of the convergencythereof and having a tongue extending downstream and through theconvergency thereof; said pivotal cam plate being disposed to be engagedby guide follower means for pivotal movement in either direction; stopmeans engageable by said tongue to predetermine the limits of movementof said cam plate upon engagement by guide follower means; said camplate having edges effecting channels in conjunction with respectivefixed convergent cam members whereby any guide follower means engagingsaid pivotal cam plate effects pivotal movement to form a channel so asto be guided thereby in the transition through said leveling mechanismto said drive means.

9. A system as set forth in claim 8, including cam means upstream ofsaid leveling mechanism for tilting all load carrying members arrivingthereat in level condition prior to entering said level mechanism.

10. A system as set forth in claim 9, wherein said cam means comprisesan offset channel leading angularly away from the path of movement ofsaid cargo carrying devices on said track means; said system comprisinga guide track upstream of said cam means and extending thereto forguiding any guide follower means into said latter channel; whereby anyload carrying member arriving in level condition is tilted prior toentry into said leveling mechanism.

11. In a system as set forth in claim 10, including a pivotal camelement effecting an extension of a side of said channel and engageableby any guide follower means of which the load carrying member is tiltedin a direction to effect an engagement on the outside of said channel;whereby said extension seryes for further tiltin guidance of load c ingmembers arriving in level con tron and wherein sai extension 18pivotally actuated out of path of guide follower means when engagedthereby outside said channel.

12. A conveyor system comprising extended track means and plurality ofcargo carrying devices movably supported thereon; a chain connectingsaid cargo carrying devices; said chain being flexible in a horizontalplane and drive means for actuating said chain; and chain retainingmeans for confining and guiding said chain whereby said chain maintainssaid cargo carrying devices on said track means; each said cargocarrying device comprising a load carrying member wherein all of saidload carrying members are closely spaced with respect to each other;said drive means comprising a sprocket wheel around which said chainpasses; each said load carrying member having a guide follower means; aguide track coacting with said guide follower means to normally maintainrespective load carrying members in level condition, said guide trackpassing arcuately around said sprocket wheel in an arcuate path andbeing sloped so as to retain its relative orientation with respect toguide follower means when said load carrying members are tilted inpassing around said sprocket wheel, said guide track being formed tomove said guide follower means radially inwardly at the upstream end ofsaid sprocket wheel for efiecting positively controlled tilt ofrespective load carrying members in order to provide spacing between theinner radial corners thereof to avoid interference in passing aroundsaid sprocket wheel.

13. A conveyor system comprising extended track means and plurality ofcargo carrying devices movably supported thereon; a chain connectingsaid cargo carrying devices; said chain being flexible in a horizontalplane and drive means for actuating said chain; and chain retainingmeans for confining and guiding said chain whereby said chain maintainssaid cargo carrying devices on said track means; including load carryingmembers comprising a plurality of relatively narrow, closely spacedslats carried by respective cargo carrying devices; said drive meanscomprising a sprocket wheel; and means for tilting said slats to effectspacing between the ends thereof to avoid interference in passing aroundsaid sprocket wheel.

14. A conveyor system comprising extended track means and plurality ofcargo carrying devices movably supported thereon; a chain connectingsaid cargo carrying devices; said chain being flexible in a horizontalplane and drive means for actuating said chain; and chain retainingmeans for confining and guiding said chain whereby said chain maintainssaid cargo carrying devices on said track means; said cargo carryingdevices having load carrying members and means whereby said members aretiltably mounted so as to be tilted in a plane transverse to the planeof movement for discharging cargo; said drive means comprising asubstantially horizontally disposed drive wheel encompassed by saidchain; levelling means for ensuring levelling of said load carryingmembers prior to movement around said wheel with said chain; and tiltmeans upstream of said latter means for ensuring tilt of all loadcarrying members prior to movement to said levelling means.

1. A conveyor system comprising extended track means and plurality ofcargo carrying devices movably supported thereon; a chain connectingsaid cargo carrying devices; said chain being flexible in a horizontalplane and drive means for actuating said chain; and chain retainingmeans for confining and guiding said chain whereby said chain maintainssaid cargo carrying devices on said track means; wherein said trackmeans comprises a pair of spaced channel members and said chainretaining means comprises a channel member carried by one of said trackmembers, said chain having a plurality of rollers disposed in said chainretaining channel member whereby said rollers are laterally confined byflanges of said latter channel member; said cargo carrying devices eachcomprising a load carrying member and a carriage, pivotal support meanswhereby said loading carrying member is tiltably carried by respectivecarriages so as to be tilted reversibly in a plane transverse of theplane of movement of said cargo carrying devices; a tilt controlmechanism incorporated in said track means and comprising a first pairof cams (225) having a common origin and divergent spacing therebetweendiverging in the direction of movement of said cargo carrying devicesand further comprising an additional pair of cams (232) having portionsspaced inwardly and parallel to respective cams in said first pair ofcams to effect a pair of divergent channels in correspondingly divergentdirections; guide follower means carried by said cargo carrying devicesreceivable in either divergent channel and connected to respective loadcarrying members to effect tilt thereof when said guide follower meansis received in one of said channels; including a pair of switch leversfor effecting diverting of said guide follower means selectively toeither divergent channel.
 2. A system as set forth in claim 1, whereineach cam of said first pair of cams has a guide member pivotally mountedat a downstream end thereof and effecting an elongation of therespective divergent channel; wherein said guide members can be engagedby and pivoted out of the path of the guide follower means of loadcarrying members which have been previously tilted.
 3. A conveyor systemcomprising extended track means and plurality of cargo carrying devicesmovably supported thereon; a chain connecting said cargo carryingdevices; said chain being flexible in a horizontal plane and drive meansfor actuating said chain; and chain retaining means for confining andguiding said chain whereby said chain maintains said cargo carryingdevices on said track means; said cargo carrying devices each comprisinga load carrying member and a carriage, pivotal support means wherebysaid load carrying member is tiltably carried by respective carriages soas to be tilted reversibly in a plane transverse of the plane ofmovement of said cargo carrying devices; a tilt control mechanismincorporated in said track means and comprising a pair of cams (225)having divergent spacing therebetween, said cams diverging in thedirection of movement of said cargo carrying devices; said tilt controlmechanism further comprising an additional pair of cams (232) havingportions spaced inwardly and parallel to respective cams in said firstpair of cams to effect channels in correspondingly divergent directions;and guide follower means carried by said cargo carrying devicesreceivable in said channels and connected to respective load carryingmembers to effect tilt thereof when said guide follower means isreceived in one of said channels, including a pair of switch levers toeffect diverting of said guide follower means selectively to eitherdivergent channel; said switch levers being spacedly mounted and havingrespective opposed edges substantially parallel and normally forming aguide channel intermediate said pairs of cam members, means pivotallyactuating said levers; actuating means for pivotally actuating saidlevers; each lever effecting an extension of a side of a respectivedivergent channel when it is actuated to thereby effect diverting;wherein said switch levers effect a path througH the spacingtherebetween when not actuated so as to guide said guide follower meansthrough said tilt control mechanism without effecting tilting, andwherein either lever, when actuated, guides said follower means to arespective divergent channel to effect tilting.
 4. A system as set forthin claim 3, and respective spring bias means for normally maintainingsaid switch levers in position to effect said spacing therebetween, saidactuating means for said levers being selectively operable for eitherlever pivotally.
 5. A conveyor system comprising extended track meansand plurality of cargo carrying devices movably supported thereon; achain connecting said cargo carrying devices; said chain being flexiblein a horizontal plane and drive means for actuating said chain; andchain retaining means for confining and guiding said chain whereby saidchain maintains said cargo carrying devices on said track means; saidcargo carrying devices each comprising a carriage having a load carryingmember and said load carrying members being tiltably carried byrespective carriages so as to be tilted reversibly in a plane transverseof the plane of movement of said cargo carrying devices; a tilt controlmechanism and a guide track leading thereto; said tilt control mechanismcomprising a pair of cams (225) having divergent spacing therebetween,said cams diverging in the direction of movement of said cargo carryingdevices, and said tilt control mechanism further comprising anadditional pair of cams (232) having portions spaced inwardly andparallel to respective cams of said first pair of cams to form divergentchannels; respective load carrying members having guide follower means(132) receivable by said guide track (35) for guidance to said divergentchannels whereby to effect tilting in a respective rotative directionwhen said guide follower means is received in one of said divergentchannels, including a pair of switch levers (238R, 238L) for effectingdiverting of said guide follower means selectively from said guide trackinto either channel; each cam of said first pair of cams (225) having apivotally mounted extension end (470) thereof effecting an elongation ofthe respective divergent channel; the said pivotally mounted extensionends being engageable by unguided guide follower means entering saidtilt control mechanism so as to be swung out of the path of said guidefollower means, thus permitting said guide follower means to moveunimpeded exteriorly of either divergent channel.
 6. A system as setforth in claim 5, said guide track being disposed in alignment with thespacing between said switch levers when said switch levers are notactuated; and cam members disposed on opposite sides of said guide trackto be engaged by any guide follower means to effect full tilting of therespective load carrying members in the event that any such guidefollower means is approaching said tilt control mechanism askew of saidguide track, in order to insure clearance of any such guide followermeans in respect to said tilt control mechanism to move withoutinterference therepast.
 7. A conveyor system comprising extended trackmeans and plurality of cargo carrying devices movably supported thereon;a chain connecting said cargo carrying devices; said chain beingflexible in a horizontal plane and drive means for actuating said chain;and chain retaining means for confining and guiding said chain wherebysaid chain maintains said cargo carrying devices on said track means;wherein each said cargo carrying device comprises a carriage having aload carrying member with a support post pivotally carried by therespective carriage, said load carrying members and said support postshaving a center of gravity disposed in a vertical plane with the pivotalaxis thereof when said load carrying member is in level position andsaid center of gravity being disposed above said pivotal axis, wherebywhen said load carrying member is in tilted position it remains intilted posItion by virtue of the displaced center of gravity; said trackmeans including a tilt control mechanism and having a guide trackextending to said tilt control mechanism upstream thereof and acontinuation of said guide track extending from said tilt controlmechanism downstream thereof; said tilt control mechanism comprising aplurality of members effecting divergent channels divergingdirectionally downstream; switch control means intermediate saiddivergent channels comprising levers having a spacing therebetweenaligned with said guide tracks and effecting a central channel inconjunction therewith and relative to the divergency of said divergentchannels; said support posts having respective guide follower meansmovable from said upstream guide track through said central channel tothe downstream guide track and maintaining said posts vertical so thatrespective load carrying members are maintained level when respectivecargo carrying devices move past said tilt control mechanism; means foractuating either of said switch levers to guide a guide follower meansinto a diverging channel for effecting tilt of a respective loadcarrying member; cam means (212) upstream of said switch levers disposedadjacent said upstream guide track to tiltably divert any guide followermeans misaligned in approaching said tilt control mechanism so as topermit passage thereof without interference with said tilt controlmechanism.
 8. A conveyor system comprising extended track means andplurality of cargo carrying devices movably supported thereon; a chainconnecting said cargo carrying devices; said chain being flexible in ahorizontal plane and drive means for actuating said chain; and chainretaining means for confining and guiding said chain whereby said chainmaintains said cargo carrying devices on said track means; wherein eachsaid cargo carrying device comprises a carriage having a load carryingmember with a support post pivotally carried by the respective carriage,said load carrying members and said support posts having a center ofgravity disposed in a vertical plane with the pivotal axis thereof whensaid load carrying member is in level position and said center ofgravity being disposed above said pivotal axis, whereby when said loadcarrying member is in tilted position it remains in tilted position byvirtue of the displaced center of gravity; said track means comprising aleveling mechanism upstream of said drive means for leveling loadcarrying members arriving at said leveling mechanism in tiltedcondition; said leveling mechanism comprising a pair of fixed convergingcam members and said support posts having guide follower meansengageable with either of said cam members dependent upon respectivedirection of tilt of said support posts, whereby said cam memberseffecting swinging of support posts to substantially vertical conditionto level respective load carrying members; guide track means extendingfrom the convergent ends of said cam members to said drive means toreceive said guide follower means as they leave said convergent endswith the respective posts substantially vertical; and a pivotal camplate intermediate said fixed convergent cam members and pivotallymounted upstream of the convergency thereof and having a tongueextending downstream and through the convergency thereof; said pivotalcam plate being disposed to be engaged by guide follower means forpivotal movement in either direction; stop means engageable by saidtongue to predetermine the limits of movement of said cam plate uponengagement by guide follower means; said cam plate having edgeseffecting channels in conjunction with respective fixed convergent cammembers whereby any guide follower means engaging said pivotal cam plateeffects pivotal movement to form a channel so as to be guided thereby inthe transition through said leveling mechanism to said drive means.
 9. Asystem as set forth in claim 8, including cam means upstream of saidleveling mechanism for tilting all load cArrying members arrivingthereat in level condition prior to entering said level mechanism.
 10. Asystem as set forth in claim 9, wherein said cam means comprises anoffset channel leading angularly away from the path of movement of saidcargo carrying devices on said track means; said system comprising aguide track upstream of said cam means and extending thereto for guidingany guide follower means into said latter channel; whereby any loadcarrying member arriving in level condition is tilted prior to entryinto said leveling mechanism.
 11. In a system as set forth in claim 10,including a pivotal cam element effecting an extension of a side of saidchannel and engageable by any guide follower means of which the loadcarrying member is tilted in a direction to effect an engagement on theoutside of said channel; whereby said extension serves for furthertilting guidance of load carrying members arriving in level conditionand wherein said extension is pivotally actuated out of path of guidefollower means when engaged thereby outside said channel.
 12. A conveyorsystem comprising extended track means and plurality of cargo carryingdevices movably supported thereon; a chain connecting said cargocarrying devices; said chain being flexible in a horizontal plane anddrive means for actuating said chain; and chain retaining means forconfining and guiding said chain whereby said chain maintains said cargocarrying devices on said track means; each said cargo carrying devicecomprising a load carrying member wherein all of said load carryingmembers are closely spaced with respect to each other; said drive meanscomprising a sprocket wheel around which said chain passes; each saidload carrying member having a guide follower means; a guide trackcoacting with said guide follower means to normally maintain respectiveload carrying members in level condition, said guide track passingarcuately around said sprocket wheel in an arcuate path and being slopedso as to retain its relative orientation with respect to guide followermeans when said load carrying members are tilted in passing around saidsprocket wheel, said guide track being formed to move said guidefollower means radially inwardly at the upstream end of said sprocketwheel for effecting positively controlled tilt of respective loadcarrying members in order to provide spacing between the inner radialcorners thereof to avoid interference in passing around said sprocketwheel.
 13. A conveyor system comprising extended track means andplurality of cargo carrying devices movably supported thereon; a chainconnecting said cargo carrying devices; said chain being flexible in ahorizontal plane and drive means for actuating said chain; and chainretaining means for confining and guiding said chain whereby said chainmaintains said cargo carrying devices on said track means; includingload carrying members comprising a plurality of relatively narrow,closely spaced slats carried by respective cargo carrying devices; saiddrive means comprising a sprocket wheel; and means for tilting saidslats to effect spacing between the ends thereof to avoid interferencein passing around said sprocket wheel.
 14. A conveyor system comprisingextended track means and plurality of cargo carrying devices movablysupported thereon; a chain connecting said cargo carrying devices; saidchain being flexible in a horizontal plane and drive means for actuatingsaid chain; and chain retaining means for confining and guiding saidchain whereby said chain maintains said cargo carrying devices on saidtrack means; said cargo carrying devices having load carrying membersand means whereby said members are tiltably mounted so as to be tiltedin a plane transverse to the plane of movement for discharging cargo;said drive means comprising a substantially horizontally disposed drivewheel encompassed by said chain; levelling means for ensuring levellingof said load carrying members prior to movement around said wheel withsaid chAin; and tilt means upstream of said latter means for ensuringtilt of all load carrying members prior to movement to said levellingmeans.